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US 12,667,280 B2Granted
Estimation device, estimation method, and program recording medium
AssigneeNEC Corporation
InventorsChenhui Huang, Kenichiro Fukushi, Zhenwei Wang, Hiroshi Kajitani, Fumiyuki Nihey, Kentaro Nakahara
Life of this patent
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Abstract
An estimation device that includes a detection unit that detects a terminal stance period from time-series data of sensor data based on a physical quantity related to movement of a foot measured by a sensor provided at a foot portion, a feature amount extraction unit that extracts a feature amount from an angular waveform in a coronal plane during the terminal stance period, and a presumption unit that estimates a degree of pronation/supination of the foot by using the feature amount extracted from the angular waveform in the coronal plane.
Claims17
An estimation device comprising:
- an inertial measurement sensor installed on a foot portion, the inertial measurement sensor comprising a three-axis accelerometer and a three-axis gyroscope configured to measure spatial acceleration and spatial angular velocity and output time-series data based on the spatial acceleration and the spatial angular velocity;
- at least one memory storing instructions;
- and
- at least one processor connected to the at least one memory and configured to execute the instructions to:
- detect a terminal stance period from the time-series data based on a physical quantity related to movement of a foot measured by the inertial measurement sensor provided at the foot portion, the detecting the terminal stance period from the time-series data comprising converting the time-series data from a local coordinate system to a world coordinate system and detecting the terminal stance period as a period from heel lift to opposite heel strike based on an inflection point of roll angular acceleration;
- extract a feature amount from an angular waveform in a coronal plane during the terminal stance period, the angular waveform being a pitch angle about a Y-axis in the coronal plane (ZX plane), and the feature amount comprising at least one of an average value, a weighted average value, and an integral value within the terminal stance period;
- estimate a degree of pronation/supination of the foot by inputting the feature amount extracted from the angular waveform in the coronal plane to a presumption model, the presumption model generated by learning a data set in which the feature amount extracted from the angular waveform in the coronal plane is an explanatory variable and a center of pressure excursion index (CPEI) obtained from a foot pressure distribution measured by a pressure sensor is an objective variable;
- and
- output the estimation result regarding the degree of pronation/supination of the foot.
6 more elements
An estimation method that causes a computer to execute processes comprising:
- measuring, by an inertial measurement sensor including a three-axis accelerometer and a three-axis gyroscope, spatial acceleration and spatial angular velocity and outputting time-series data based on the spatial acceleration and the spatial angular velocity;
- detecting a terminal stance period from the time-series data based on a physical quantity related to a movement of a foot measured by the inertial measurement sensor provided at the foot portion, the detecting the terminal stance period from the time-series data comprising converting the sensor data from a local coordinate system to a world coordinate system and detecting the terminal stance period as a period from heel lift to opposite heel strike based on an inflection point of roll angular acceleration;
- extracting a feature amount from an angular waveform in a coronal plane during the terminal stance period, the angular waveform being a pitch angle about a Y-axis in the coronal plane (ZX plane), and the feature amount comprising at least one of an average value, a weighted average value, and an integral value within the terminal stance period;
- estimating a degree of pronation/supination of the foot by inputting the feature amount extracted from the angular waveform in the coronal plane to a presumption model, the presumption model generated by learning a data set in which the feature amount extracted from the angular waveform in the coronal plane is an explanatory variable and a center of pressure excursion index (CPE) obtained from a foot pressure distribution measured by a pressure sensor is an objective variable;
- and
- outputting the estimation result regarding the degree of pronation/supination of the foot.
3 more elements
A non-transitory program recording medium that stores a program configured to cause a computer to execute one or more processes comprising:
- measuring, by an inertial measurement sensor including a three-axis accelerometer and a three-axis gyroscope, spatial acceleration and spatial angular velocity and outputting time-series data based on the spatial acceleration and the spatial angular velocity;
- detecting a terminal stance period from the time-series data based on a physical quantity related to a movement of a foot measured by the inertial measurement sensor provided at the foot portion, the detecting the terminal stance period from the time-series data comprising converting the sensor data from a local coordinate system to a world coordinate system and detecting the terminal stance period as a period from heel lift to opposite heel strike based on an inflection point of roll angular acceleration;
- extracting a feature amount from an angular waveform in a coronal plane during the terminal stance period, the angular waveform being a pitch angle about a Y-axis in the coronal plane (ZX plane), and the feature amount comprising at least one of an average value, a weighted average value, and an integral value within the terminal stance period;
- estimating a degree of pronation/supination of the foot by inputting the feature amount extracted from the angular waveform in the coronal plane to a presumption model, the presumption model generated by learning a data set in which the feature amount extracted from the angular waveform in the coronal plane is an explanatory variable and a center of pressure excursion index (CPE) obtained from a foot pressure distribution measured by a pressure sensor is an objective variable;
- and
- outputting the estimation result regarding the degree of pronation/supination of the foot.
3 more elements
Dependencies are inferred from the claim text.